A vehicular lamp, such as, for example, a vehicular headlight employs a light emitting device such as, for example, a light emitting diode (LED) serving as a semiconductor light source, or a light emitting device such as, for example, a filament bulb.
Japanese Patent Laid-Open Publication No. 2013-109939 discloses a technology of detecting an abnormality such as a disconnection, a short-circuit, or a ground fault which may occur in an LED.
Japanese Patent Laid-Open Publication No. 2011-192865 discloses a circuit in which a bypass circuit is provided for each of a plurality of LEDs connected in series so that the LEDs may be turned OFF when the bypass route is turned ON.